1. Field of the Invention
The invention relates to construction line reels, and more particularly, to a stronger and more convenient construction line reel on which a disposable spool holding wound construction line can be mounted and used repeatedly and, when the line is expended or no longer useful, can be re-used with a replacement spool of new line.
2. Description of the Prior Art
Construction workers, including carpenters, masonry workers, steel workers, and the like are frequently required to use long lengths of heavy string, hereinafter referred to as construction line, pulled tight between various points in order to establish straight lines. Straight lines are often necessary to aide in taking measurements or to properly align structural elements during construction. Since the use of a line reel for construction may subject the line reel to numerous environmental and operational hazards and conditions, the line reel must be rugged and capable of withstanding harsh use and treatment. Therefore, an inexpensive, rugged, and easy to use line reel for dispensing construction line is needed. Furthermore, many construction tasks are performed at high heights in partially completed structures where construction equipment, construction materials, and other workers may pose obstacles or hazards to the worker attempting to dispense the construction line, causing dangerous working conditions where the worker must be particularly careful and constantly alert. Therefore, it is desirable that the line reel be capable of being easily held and used with one hand, instead of requiring two hands, so that the construction worker will be able to focus his attention on maintaining his or her safety. These and other problems and concerns relating to use of construction line are described in more detail in the U.S. Pat. No. 4,285,477, issued to Oxendahl et al., which is incorporated herein by reference.
The construction line reel that is the subject of the U.S. Pat. No. 4,285,477, issued to Oxendahl et al. solved many of the problems described above. However, after the line is cut a number of times, tangled in knots, or just worn out, it has to be replaced. Since construction line is often purchased prewound around a cardboard or plastic spool, it would have to be unwound from the spool and wound onto the reel, which is a time consuming and sometimes frustrating task. Therefore, construction workers often prefer to just throw away the old line with the spool and all and just start with a new reel that already has new line on it. That approach works, but it is somewhat wasteful. Further, it does not solve a similar problem in manufacturing, wherein the line has to be unwound from spools and wound onto the reels. While this task can be automated and is easier than a construction worker doing it by hand, it is still a manufacturing step that costs.
Our rotatable handle for a disposable spool that is described in U.S. Pat. No. 5,664,739, which is also incorporated herein by reference, provided a solution to the problems described above by enabling a conventional spool of construction line to be fitted easily and quickly with a rotatable handle. In other words, rather than outfitting a reel with construction line, as was the conventional prior art approach, a spool of construction line could instead be outfitted with a rotatable reel and handle. That approach is still valid and a preferred manner of handling construction line. However, the rotatable reel apparatus described in U.S. Pat. No. 5,664,739 still had some deficiencies. For example, the lack of a shaft extending all the way through the cord spool leaves the end cap subject to being rotated in relation to the midsection or even pulled out of the cord spool by the construction line when the construction is being unwound or pulled in tension in a direction that is more parallel than perpendicular to the spool axis. While the alternate embodiment of FIGS. 8-13 of U.S. Pat. No. 5,664,739 helped, the center connection of the cap shank to the midsection shank inside the spool still leaves the structure a little too flimsy as well as inaccessible for detachment without destroying the old spool. The latter deficiency is particularly significant if there is still a substantial amount of old construction line left on the old spool to make it difficult to even tear or cut through the old spool to access the shank latch or in situations where the user prefers to save the old spool of line for some other use.